Masking tape and its use

ABSTRACT

A masking tape comprising:  
     a) a heat resistant adhesive tape comprising a flexible sheet backing and a pressure sensitive adhesive composition,  
     b) a masking material, which is laminated in an edge region of the pressure-sensitive adhesive composition, said masking material being capable of adhering to paint and absorbing paint,  
     c) a masking sheet, which is laminated onto the very same edge region of the pressure-sensitive adhesive composition,  
     d) the masking sheet covering the masking material on a side thereof.

[0001] The invention relates to a masking tape, especially for coveringcertain parts when painting cars, as well as to the use of this tape. Inparticular, masking is provided for medium to large surfaces, which mustnot come into contact with paint in touch-up work in automobile paintshops.

[0002] Such masking tapes or shrouds are known and their use iswidespread. Standard materials are, for example, 50 g weight specialpapers or newsprint, and also folded plastic hoods (approximately 30 μmthick or 30 g/m²) or “endless” sheets from a large roll (2 m wide) aswell as “2 in 1” systems as folded polyethylene sheets with adhesivetape, including also polyethylene-coated papers with adhesive tape.

[0003] Such masking systems must fulfill especially the followingrequirements:

[0004] Paint adhesion—After oven drying, the paint must not fall fromthe masking material onto the fresh paint.

[0005] Waste—A small volume of waste is important, since it determinesthe price of disposal.

[0006] Number of persons—Normally, an automobile is painted by only oneperson. It should therefore be easy for one person to apply the masking.

[0007] Number of steps—Few steps, which can be carried out quickly, arerequired.

[0008] Material consumption—An adhesive tape, capable of withstandingthe temperatures encountered, is required for applying the masking. Theconsumption of masking material and adhesive tape should be small.

[0009] The previously known masking tapes and the like fulfill theserequirements only to a limited extent. Advantages Disadvantages PapersOptimum paint adhesion Paint bleeds through especially even when paintis when applied more heavily in applied heavily in the edge region theedge region Masking must be equipped Low costs subsequently withadhesive tape Not dispensed directly on the vehicle. Therefore too muchmaterial is consumed at times, since sometimes too much or too littlepaper is dispensed. Shrouds No paint bleeds through Paint adhesion notoptimum The whole of the vehicle Relatively expensive is covered Highmaterial consumption, The plastic shroud can since the whole automobilemust easily be incised, in order always be covered to expose the area tobe Hoods generally are steeped in painted paint. As a result, theautomobiles cannot be marshaled in the covered state. Endless Seeshrouds See shrouds (exception: material sheets consumption, sinceautomobiles can also be covered partially) 2 in 1 - Paint does not bleedOptimum result only when both Systems through sheet products are used(that is, paper folded No paint bleed-through in the edge region andsheet for sheets with and adequate adhesion larger surface). maskingtape in the case of Both products are always polyethylene-coatedfurnished with adhesive tape. paper Dispensed at vehicle ConvenientSlight Poly- Little waste since Due to the coating (composite) ethylene-polyethylene and the bleaching (white), paper coated paper film is only10 μm thick is not environmentally friendly with and is expensive.masking tape

[0010] It was an object of the invention to provide a remedy here and,in particular, to create a masking tape, for which an inexpensive,absorptive or adhesive material can be used, which has, in particular,good adhesion for paint, etc. (paint adhesion).

[0011] This objective is accomplished by a masking tape, which ischaracterized in greater detail in the claims.

[0012] With that, the invention combines the very good properties ofabsorptive or adhesive material with respect to the adhesion of paintand the very good properties of sheets in relation to reliabilityagainst bleed-through in a convenient product.

[0013] With that, the product consists of three products in one andtherefore can be referred to as a “3 in 1” product. The components arean absorptive or adhesive material, an adhesive tape with a flexiblesheet backing and a sheet. The following are preferred:

[0014] for example, paper: as absorptive material, unbleached Kraftpaper with a weight of 30 to 40 g/m², 20 to 40 cm wide.

[0015] sheet: 10 μm (=10 g/m² of pretreated (corona) polyethylene sheet(surface tension approximately 38 dynes), width of the sheet between 500mm and 2000 mm depending on the application, variable length usuallybetween 10 and 30 m.

[0016] adhesive tape: with flexible sheet backing, especially ofpolypropylene and particularly of PVC, soft PVC being preferred,approximately 80 to 150 μm thick and a resistance to heat at 80° C. to150° C., such as tesa 41^ 74, 4244, 4244 N2, 4215 and 7133, on themarket from Beiersdorf AG.

[0017] The absorptive material, especially woven material, nonwovenmaterial or paper, is intended to absorb the heavier application ofpaint in the edge region of the painting and to adhere reliably alsoafter oven drying, so that paint cannot fall onto the still soft,freshly painted surface. The sheet is prepared by the corona treatmentpreferably so that a paint mist is fixed reliably. Furthermore, thesheet, for example, prevents paint bleeding through the paper onto thefreshly painted surface.

[0018] In particular, the following product advantages result:

[0019] Optimum paint adhesion a) in the critical edge region, forexample, the absorptive paper and b) on the remaining masked surface bythe specially pretreated sheet.

[0020] Optimum protection against paint bleed-through by the film.

[0021] Appreciably less waste from the thin sheet (approximately a fifthof that from 50 g weight paper).

[0022] Handling by only one person, due to the convenient format and thepre-manufactured product.

[0023] Optimum material consumption a) in relation to the maskingmaterial due to the direct dispensing at the vehicle and b) with respectto the adhesive tape because of the standardized width, such as 25 mm.

[0024] Time saved by few working steps (3 in 1).

[0025] The following are the product advantages over the “2 in 1”system:

[0026] For the edge region, particularly inexpensive, untreated standardKraft paper can be used, with which the painter is familiar.

[0027] The edge region and the large surface are covered in one step.

[0028] Adhesive tape is required only once.

[0029] In the following, the invention is described by means of anexample without, however, being limited unnecessarily. In the drawing,

[0030]FIG. 1 shows a diagrammatic side view of an inventive masking tapewith a folded masking sheet,

[0031]FIG. 2 shows a view, similar to that of FIG. 1, however with apartially unfolded masking sheet and

[0032]FIG. 3 shows a view, like that in FIG. 1, the masking sheet beingfully unfolded now.

[0033] In detail, the FIGS. 1 to 3 show an adhesive tape 1 with a sheetbacking 2 of soft PVC, which is 100 μm thick and is resistant totemperatures up to 150° C., and a pressure-sensitive adhesivecomposition 3. In particular, a heat-resistant, so-called masking tape,which withstands oven drying up to 130° C. (1 hour), such as thatcommercially obtainable as tesa 4309 from Beiersdorf AG, Germany, andhaving a width of 25 mm, a thickness of 170 μm and an adhesion to steelof 8.75 N/25 mm, is suitable. On the one edge region 4 of this adhesivetape 1, unbleached Kraft paper as masking paper 5, 30 cm wide, with aweight of 35 g/m², is glued in a width of 3 mm. Next to this maskingpaper 5, a masking sheet 6, namely a 10 μm thick corona-treatedpolyethylene film, 1 m wide and folded, is glued onto the next part ofthis edge region 4 in a width of 3 mm.

[0034] The folding of the masking sheet 6 is known and is undertakenparticularly in the manner known and familiar to the user, the whole ofthe masking tape being rolled up into a roll for easier handling.Preferably, the folding is carried out so that the folds of the maskingsheet 6 lie on top of one another in the direction of the maskingmaterial 5 and are held by the latter in the folded state. This has theadvantage, for example, that an automobile, equipped with an inventivemasking tape and prepared for painting, can still be moved and entered,while the masking tape is installed but not yet unfolded. Only when theautomobile is at its appointed place at the appointed time, is themasking tape unfolded by slightly lifting the masking material 5, thatis, the masking sheet 6 falls down without the intervention of furthermeasures or work.

1. A masking tape comprising: a) a heat resistant adhesive tape comprising a flexible sheet backing and a pressure-sensitive adhesive composition, b) a masking material, which is laminated in an edge region of the pressure-sensitive adhesive composition, said masking material being capable of adhering to paint and absorbing paint, c) a masking sheet, which is laminated onto the very same edge region of the pressure-sensitive adhesive composition, d) the masking sheet covering the masking material on a side thereof.
 2. The masking tape of claim 1, wherein the adhesive tape is a heat-resistant adhesive tape for the automobile painter, a so-called fine line tape, with a heat resistance especially at temperatures up to 130° C. (1 hour), especially one with a sheet backing of polypropylene or particularly of soft PVC.
 3. The masking tape of claim 1, wherein the adhesive tape is 15 to 75 mm wide and, in particular 19 to 30 mm wide.
 4. The masking tape of claim 1, wherein the masking material consists of paper, woven fabric, nonwoven fabric or another sheet material capable of adhering.
 5. The masking tape of claim 1, wherein the masking material is unbleached Kraft paper, having a weight of 30 to 40 g/m² and a width especially of 15 to 50 cm and particularly of 20 to 40 cm.
 6. The masking tape of claim 1, wherein the masking sheet has a thickness of 7 to 40 mm and especially of 8 to 20 mm, consists especially of polyolefin, particularly polyethylene and especially is corona pretreated, and the width, in particular, is 0.5 to 2 m.
 7. The masking tape of claim 1, wherein the masking sheet is folded so that it can be extended, follows, in particular, the external dimensions of the masking material and is folded against the masking material in accordion fashion.
 8. The masking tape of claim 1, wherein a portion of the edge region of the pressure-sensitive adhesive composition to which the masking material adheres is 1 to 5 and particularly 2 to 4 mm wide and a portion of the edge region of the pressure-sensitive adhesive composition to which the masking sheet adheres is 1 to 5 and, in particular, 2 to 4 mm wide.
 9. The masking tape of claim 1, wherein the tape is rolled up into a roll, the masking sheet is folded and the height of the roll corresponds approximately to the width of the masking material plus the width of the adhesive tape.
 10. A method comprising applying the masking tape of claim 1 to a part, especially an automobile part, to be masked, and then subjecting said part to a surface treatment, especially painting. 